DE102020108071A1 - Wrapping paper for smoking articles with improved ash appearance - Google Patents

Abstract

A wrapping paper for smoking articles is shown, which comprises pulp fibers loaded with calcium carbonate particles, the mass of the pulp fibers loaded with calcium carbonate particles being at least 1% of the mass of the wrapping paper and the calcium carbonate particles in the pulp fibers loaded with calcium carbonate particles at least 5% and at most 80% of the mass of the Calcium carbonate particles make up pulp fibers loaded.

Description

FIELD OF THE INVENTION

The invention relates to a wrapping paper for smoking articles which contains cellulose fibers loaded with filler particles which give the paper particularly favorable properties. In particular, the ash of a smoking article made from this wrapping paper has a better appearance.

BACKGROUND AND PRIOR ART

A common smoking article comprises a cylindrical rod of tobacco containing an aerosol forming material, typically tobacco or a tobacco-based material, which is wrapped in a wrapping material. In most cases, the wrapping material comprises a paper, that is to say a web-like material which contains cellulose fibers. Furthermore, a smoking article can comprise a filter which is wrapped in a filter wrapping paper, and a mouthpiece covering paper which at the same time wraps the filter and a part of the tobacco rod and thus connects the filter and the tobacco rod to one another.

When the smoking article is used, the aerosol-forming material is heated or burned so that an aerosol is formed which, when the smoking article is used, flows through the smoking article and is inhaled by the consumer.

In particular, if the aerosol-forming material is only heated but not burned, the smoking article can also comprise components that convey the aerosol or cool the aerosol, and are typically arranged between the tobacco rod and the filter.

When the tobacco rod is burned or heated to release the aerosol, the wrapping paper of the tobacco rod is thermally degraded. The wrapping paper can discolor and lose some of its mechanical stability, which is why the optical appearance of the smoking article changes. This appearance of a used or in use smoking article and in particular its tobacco rod is referred to as an ash image.

From the consumer's point of view, it is a sign of high quality of the smoking article if it has a good ash appearance, i.e. if the tobacco rod essentially retains its cylindrical shape after burning or heating, is of a uniform white color and no dark particles, for example tobacco particles or their ashes protrude through the wrapping material.

Various possibilities are known from the prior art for improving the ash appearance of a smoking article. For example, the weight per unit area of the wrapping paper can be increased or fire salts such as trisodium citrate or tripotassium citrate can be added or their content increased. However, these possibilities have the disadvantage that they increase the proportion of non-tobacco materials in the smoking article and can thus negatively change the taste of the smoking article. There is therefore an interest in improving the ash appearance of a smoking article without adding new components to the wrapping paper or significantly increasing its mass. This interest does not only apply to the wrapping paper which directly wraps the aerosol-forming material, but generally also to wrapping papers for other components of the smoking article, in particular those which can also be exposed to the high temperatures of the aerosol.

SUMMARY OF THE INVENTION

In the following, “wrapping paper” should be understood to mean any paper that wraps the smoking article or at least one of its components.

The invention is based on the object of providing a wrapping paper for smoking articles which gives the smoking article a good ash appearance without the need to increase the weight of the wrapping paper significantly or to add unusual components to the wrapping paper.

This object is achieved by a wrapping paper for a smoking article according to claim 1, a laminate according to claim 32 and a smoking article according to claim 33, which comprises said wrapping paper. Advantageous further developments are given in the dependent claims.

The inventor has found that this object can be achieved in that the wrapping paper contains cellulose fibers which are loaded with calcium carbonate particles. Cellulose fibers and calcium carbonate particles are common components of wrapping papers for smoking articles, but in the prior art the calcium carbonate particles are not connected to the cellulose fibers, but are only arranged between the cellulose fibers. Such calcium carbonate particles are referred to as "free calcium carbonate particles" in order to distinguish them from the calcium carbonate particles with which the cellulose fibers are loaded, i.e. connected. Such cellulose fibers loaded with calcium carbonate particles can be produced, for example, by precipitation of the calcium carbonate with the simultaneous presence of the cellulose fibers with appropriate management of the precipitation process.

Specifically, the wrapping paper according to the invention comprises cellulose fibers loaded with calcium carbonate particles, the mass of the cellulose fibers loaded with calcium carbonate particles being at least 1% of the weight of the wrapping paper and the calcium carbonate particles in the cellulose fibers loaded with calcium carbonate particles making up at least 5% and at most 80% of the mass of the cellulose fibers loaded with calcium carbonate particles .

The inventor assumes that the calcium carbonate particles connected to the cellulose fibers form a framework that remains after the thermal degradation of the cellulose fibers and thus ensures the stability of the thermally degraded wrapping paper and thus prevents, for example, ash particles of the aerosol-forming material from penetrating the wrapping paper. In this way, the overall ash appearance of the smoking article is improved. In contrast, the free calcium carbonate particles do not form such framework-like structures and therefore do not contribute to the same extent to improving the ash structure. Therefore, with a comparable ash appearance, the mass of calcium carbonate particles in the wrapping paper can be reduced or the mass of the wrapping paper can be reduced overall by using cellulose fibers loaded with calcium carbonate particles. This also reduces the influence of the wrapping paper on the taste of the smoking article.

The wrapping paper according to the invention offers particular advantages if it has high air permeability. A conventional wrapping paper with high air permeability has more and larger pores and is therefore even more difficult to form a mechanically stable framework during thermal degradation, which is why the ash appearance is often unacceptable. This effect can be largely compensated for by the cellulose fibers loaded with calcium carbonate particles in the wrapping paper according to the invention.

In some embodiments, all of the pulp fibers in the wrapping paper are loaded with calcium carbonate particles. However, it can also be provided that the wrapping paper contains not only the cellulose fibers loaded with calcium carbonate particles but also cellulose fibers that are not loaded with calcium carbonate particles. The proportion of such cellulose fibers is preferably at least 1% and at most 95%, particularly preferably at least 10% and at most 80% and very particularly preferably at least 20% and at most 70%, each based on the mass of the wrapping paper.

Both the cellulose fibers and the cellulose fibers loaded with calcium carbonate particles can be obtained from coniferous woods such as spruce, pine or fir, from hardwoods such as eucalyptus, birch or beech, or from other plants such as hemp, flax, jute, sisal, abaca or cotton . The cellulose fibers can also be obtained from regenerated cellulose, such as viscose fibers, modal fibers, Lyocell® or Tencel®. Mixtures of cellulose fibers of various origins can be used.

The wrapping paper according to the invention contains at least 1% cellulose fibers loaded with calcium carbonate particles. The wrapping paper can be uncoated or coated. The cellulose fibers loaded with calcium carbonate particles can be located in the bulk of the wrapping paper or in an optional coating on the wrapping paper. If there are cellulose fibers loaded with calcium carbonate particles in the mass of the wrapping paper, the proportion of cellulose fibers loaded with calcium carbonate particles is preferably higher and is at least 5% and at most 80% and particularly preferably at least 30% and at most 70%, each based on the weight of the wrapping paper . If the cellulose fibers loaded with calcium carbonate particles are exclusively in the optional coating of the wrapping paper, then the proportion of cellulose fibers loaded with calcium carbonate particles is preferably at least 1% and at most 30% and particularly preferably at least 2% and at most 25%, each based on the mass of the Wrapping paper.

A high proportion of cellulose fibers loaded with calcium carbonate particles makes it possible to reduce the proportion of free calcium carbonate particles and at the same time to improve the ash structure. It is even possible that by using the cellulose fibers loaded with calcium carbonate particles, the total content of the calcium carbonate particles in the wrapping paper can be reduced without deteriorating the ash appearance. The cellulose fibers loaded with calcium carbonate particles form fewer hydrogen bonds, however, so that the overall tensile strength of the wrapping paper can decrease. Therefore, the amount of cellulose fibers loaded with calcium carbonate particles in the wrapping paper cannot be selected to be arbitrarily high, in particular when the cellulose fibers are loaded with a large amount of calcium carbonate particles.

The cellulose fibers loaded with calcium carbonate particles are preferably obtained from hardwoods such as eucalyptus, birch or beech. These cellulose fibers are generally less mechanically stressed during the production of the wrapping paper, for example during grinding, so that fewer calcium carbonate particles can be lost in the production process.

The calcium carbonate particles of the cellulose fibers loaded with calcium carbonate particles are preferably precipitated calcium carbonate particles and particularly preferably precipitated calcium carbonate particles with a rhombohedral structure. These structures can be produced particularly well on the cellulose fibers in a precipitation process.

The mass of the calcium carbonate particles based on the mass of the cellulose fibers loaded with calcium carbonate particles is at least 5% and at most 80% in the wrapping paper according to the invention. However, it is preferably at least 10% and at most 70% and very particularly preferably at least 20% and at most 60%. In the preferred intervals, there is a particularly favorable compromise between the desired improvement in the ash pattern and the undesired reduction in tensile strength.

The wrapping paper can also contain free fillers that are not associated with the pulp fibers. The proportion of free fillers is preferably at least 1% and at most 40%, particularly preferably at least 5% and at most 35% and very particularly preferably at least 10% and at most 30%, each based on the weight of the wrapping paper. These fillers can serve to influence the whiteness, the opacity and the pore structure of the wrapping paper. However, a high content of free fillers reduces the tensile strength of the wrapping paper. With the free fillers there is also the risk that they will settle as dust in further processing steps, for example when producing a smoking article from the wrapping paper, and thus shorten the necessary cleaning intervals for the machines. In the preferred intervals, the advantages of using free fillers predominate.

The free fillers in the wrapping paper are preferably carbonates, oxides, hydroxides and silicates. Particularly preferred fillers are calcium carbonate, magnesium carbonate, magnesium oxide, magnesium hydroxide, aluminum hydroxide, titanium dioxide, talc, kaolin, calcined kaolin and mixtures thereof. Precipitated calcium carbonate is very particularly preferred.

The ratio between the mass of calcium carbonate particles contained in the pulp fibers loaded with calcium carbonate particles and the mass of free filler particles in the wrapping paper can be important for adjusting the ash appearance in relation to other properties such as whiteness, opacity and tensile strength. The ratio of the mass of calcium carbonate particles contained in the pulp fibers loaded with calcium carbonate particles and the mass of free filler particles in the wrapping paper is preferably from 5:95 to 100: 0, particularly preferably from 10:90 to 80:20 and very particularly preferably it is 10:90 to 50:50.

The wrapping paper can also contain fire salts. The fire salts influence the rate of thermal degradation of the wrapping paper and can also help to improve the ash appearance, because they partly act as an adhesive or as a sintering aid between the free filler particles and thus improve the mechanical stability of the thermally degraded wrapping paper. Fire salts are preferably used in the wrapping paper that wraps the tobacco rod.

The proportion of fire salts in the wrapping paper can be selected to be variable, the proportion preferably being at least 0.3% and at most 7%, particularly preferably at least 0.5% and at most 5% and very particularly preferably at least 0.5% and at most 3% , each based on the mass of the wrapping paper.

The fire salts can preferably be selected from the group consisting of citrates, malates, tartrates, acetates, nitrates, succinates, fumarates, gluconates, glycolates, lactates, oxyalates, Salicylates, α-hydroxycaprylates, phosphates, chlorides and hydrogen carbonates, and mixtures thereof and particularly preferably from the group consisting of trisodium citrate, tripotassium citrate and mixtures thereof.

In one embodiment of the wrapping paper, the wrapping paper is essentially provided over its entire surface with a coating that contains free calcium carbonate particles and / or cellulose fibers loaded with calcium carbonate particles. "Coated over the entire area" means that a full-area coating is intended or at least 95% of the area is coated. A suitably selected coating can further improve the ash appearance without adding unusual components to the wrapping paper. The coating increases the content of calcium carbonate particles on the paper surface, so that a stable framework can be formed more easily, which ensures the mechanical stability of the wrapping paper after its thermal degradation.

The coating can be carried out by applying a composition using methods known from the prior art, such as, for example, in a size press or a film press of a paper machine, in coating or coating units or by means of a printing machine, in particular a gravure printing machine.

A composition suitable for producing the coating comprises a solvent, preferably water, and calcium carbonate particles or cellulose fibers loaded with calcium carbonate particles. Such calcium carbonate particles, which do not belong to the calcium carbonate particles of the loaded cellulose fibers, are referred to as free calcium carbonate particles, as is the case with the wrapping paper itself. The proportion of free calcium carbonate particles in the composition can preferably be at least 0% and at most 40%, particularly preferably at least 5% and at most 30%, each based on the mass of the composition. The proportion of cellulose fibers loaded with calcium carbonate particles can preferably be at least 0% and at most 10%, particularly preferably at least 1% and at most 7%, in each case based on the mass of the composition. It should be noted that the above-mentioned coating corresponds to the applied composition in the dried state, i.e. H. in particular when the solvent has evaporated.

If the composition contains free calcium carbonate particles, the composition should contain a binder in order to fix the free calcium carbonate particles to the wrapping paper. This binder then also remains in the coating formed by the application of the composition. If the composition contains calcium carbonate particles only in the form of pulp fibers loaded with these, a binding agent is not absolutely necessary, but is also preferable for better fixation. The binder is particularly preferably selected from the group consisting of starch, starch derivatives, carboxymethyl cellulose, cellulose derivatives, polyvinyl alcohol, galactomannan, gum arabic, alginates and mixtures thereof. The starch is very particularly preferably a mechanically fragmented and chemically crosslinked starch because it is not soluble in water in the chemical sense and therefore penetrates less into the paper structure and thus less reduces the air permeability of the wrapping paper. The person skilled in the art can choose the amount of binder from experience, in particular with regard to the requirements of the application process.

The composition can comprise further components which the person skilled in the art can suitably choose, including, for example, fire salts, dyes, flavorings, humectants such as glycerol or propylene glycol, or substances for influencing the viscosity.

The composition can be applied to one or both sides of the wrapping paper. However, the composition is preferably applied to the side that is on the outside of the smoking article made therefrom. This side is generally already known during the production of the wrapping paper and in most cases the side facing away from the wire of the paper machine. The composition is therefore preferably applied to the side of the wrapping paper facing away from the wire of the paper machine, which side is also referred to as the top side.

After the applied composition has dried, the weight per unit area of the coating is preferably at least 0.5 g / m ² and at most 10 g / m ² , particularly preferably at least 1 g / m ² and at most 5 g / m ² .

In a preferred embodiment, the mass of the free calcium carbonate particles and the calcium carbonate particles of the loaded cellulose fibers in the coating taken together is at least 1% and at most 20%, particularly preferably at least 2% and at most 15% of the mass of the coated wrapping paper. The wrapping paper preferably also contains cellulose fibers loaded with calcium carbonate particles, the weight of the cellulose fibers loaded with calcium carbonate particles in the wrapping paper without the coating being preferably at least 1% and at most 70%, particularly preferably at least 1% and at most 60% of the weight of the wrapping paper , and the calcium carbonate particles in the cellulose fibers loaded with calcium carbonate particles make up at least 10% and at most 60% of the mass of the cellulose fibers loaded with calcium carbonate particles.

In a preferred embodiment, the wrapping paper according to the invention can also be part of a laminate, particularly preferably a laminate with a further material with a thermal conductivity that exceeds that of the wrapping paper by a factor of at least two, preferably at least four. In particularly preferred embodiments, the further material of the laminate is formed by an aluminum foil. Such laminates can primarily be used in smoking articles in which the aerosol-forming material is only heated but not burned in order to prevent the smoking article from being lit and smoked like an ordinary cigarette.

In a further preferred embodiment of the wrapping paper for a smoking article, the smoking article is a cigarette and the wrapping paper additionally has patterns or structures, particularly preferably bands printed in the circumferential direction, in order to reduce the tendency of the smoking article to ignite measured in accordance with ISO 12863: 2010.

The basis weight of the wrapping paper according to the invention is preferably at least 15 g / m ² and at most 150 g / m ² , particularly preferably at least 20 g / m ² and at most 120 g / m ² , very particularly preferably at least 20 g / m ² and at most 40 g / m ² . The basis weight of the wrapping paper can be determined according to ISO 536: 2019, whereby a coating, if present, counts as part of the basis weight.

The thickness of the wrapping paper according to the invention is preferably at least 10 μm and at most 200 μm, preferably at least 15 μm and at most 120 μm and very particularly preferably at least 30 μm and at most 100 μm. The thickness can be determined according to ISO 534: 2011 on a single layer of the wrapping paper. Here, too, a coating, if present, is part of the thickness of the wrapping paper.

The mechanical properties of the wrapping paper according to the invention can be important for the production of a smoking article from this wrapping paper. The essential mechanical properties include tensile strength, elongation at break and energy absorption capacity, all of which can be determined according to ISO 1924-2: 2008.

The tensile strength of the wrapping paper is preferably at least 7 N / 15 mm, particularly preferably at least 8 N / 15 mm and very particularly preferably at least 10 N / 15 mm. Since the expenditure of material and energy in papermaking to increase the tensile strength is high, it is favorable if the tensile strength is at most 100 N / 15 mm, preferably at most 80 N / 15 mm and particularly preferably at most 70 N / 15 mm. The tensile strength can be increased above all by increasing the weight per unit area and increasing the proportion of cellulose fibers, as well as by more intensive grinding of the cellulose fibers.

In order to compensate for differences in speed in the machines for producing smoking articles from the wrapping paper, it is advantageous if the wrapping paper has a certain elasticity. The elongation at break of the wrapping paper according to the invention is preferably at least 0.9% and at most 3%, particularly preferably at least 1% and at most 2%.

Another mechanical parameter that is important for the processability of the wrapping paper into a smoking article is the energy absorption capacity. The energy absorption capacity describes how much energy is required to tear the paper. For the wrapping paper according to the invention it is preferred if the energy absorption ^{capacity is at least 3 J / m 2} and at most 50 J / m ² and very particularly preferably at least 3.5 J / m ² and at most 35 J / m ² .

The whiteness (ISO brightness) of the wrapping paper can be important for its visual appearance and also for the ash appearance. It is measured according to ISO 2470-1: 2016. In general, white wrapping papers are preferred for optical reasons, so that the whiteness of the wrapping paper according to the invention is at least 80% and particularly preferably at least 90%.

The whiteness can be influenced, for example, by choosing the free fillers; in particular, the whiteness can be increased considerably with titanium dioxide.

The opacity of the wrapping paper is also important for the visual appearance. A high opacity is generally favorable because components of the smoking article are then not visible through the wrapping paper. The opacity is measured according to ISO 2471: 2008. The opacity of the wrapping paper is preferably at least 70% and particularly preferably at least 80%. Opacity can also be increased by increasing the amount of free fillers in the wrapping paper.

In certain applications of the wrapping paper according to the invention on a smoking article, its air permeability is important. In such applications, for example, when the smoking article is in use, air should flow through the wrapping paper into the smoking article in order to dilute the aerosol. The air permeability can be measured according to ISO 2965: 2019.

The air permeability of the wrapping paper according to the invention is preferably at least 0 cm ³ / (cm ² min kPa) and at most 300 cm ³ / (cm ² min kPa), particularly preferably at least 10 cm ³ / (cm ² min kPa) and at most 250 cm ³ / (cm ² · min · kPa) and very particularly preferably at least 20 cm ³ / (cm ² · min · kPa) and at most 150 cm ³ / (cm ² · min · kPa). If the wrapping paper is coated, its air permeability is lower and is at most 120 cm ³ / (cm ² min kPa), particularly preferably at most 100 cm ³ / (cm ² min kPa) and very particularly preferably at most 80 cm ³ / (cm ² · min · kPa).

In the case of conventional wrapping papers, those with high air permeability generally have a poor ash appearance, so that in this case the invention can be used particularly advantageously if the content of calcium carbonate particles connected to the cellulose fibers is increased. In a particular embodiment of the invention, the wrapping paper according to the invention comprises pulp fibers loaded with calcium carbonate particles, the mass of the pulp fibers loaded with calcium carbonate particles being at least 10% of the mass of the wrapping paper and the calcium carbonate particles in the pulp fibers loaded with calcium carbonate particles being at least 20% and at most 80% of the mass of the make up pulp fibers loaded with calcium carbonate particles and the wrapping paper has an air permeability according to ISO 2965: 2019 of at least 50 cm ³ / (cm ² · min · kPa) and at most 300 cm ³ / (cm ² · min · kPa).

The above-mentioned preferred and particularly preferred intervals for the type and amount of cellulose fibers, type and amount of cellulose fibers loaded with calcium carbonate particles, proportion of calcium carbonate particles in the cellulose fibers loaded with calcium carbonate particles, type and amount of free fillers, type and amount of fire salts, as well as the mechanical parameters such as tensile strength, elongation at break and energy absorption capacity and the optical parameters such as whiteness and opacity also apply to this particular embodiment. A coating, on the other hand, is not preferred for this particular embodiment because it can reduce the air permeability too much.

A smoking article according to the invention comprises an aerosol-forming material and the wrapping paper according to the invention. In a preferred embodiment of the smoking article, the aerosol-forming material comprises tobacco and said wrapping paper wraps the aerosol-forming material.

In a further preferred embodiment, the smoking article is a smoking article according to the invention in which the aerosol-forming material is only heated but not burned.

In a particularly preferred embodiment, the smoking article is a cigarette and the wrapping paper is a cigarette paper.

Both the wrapping paper according to the invention and the smoking article according to the invention can be produced by methods known per se in the prior art.

Figure list

• 1 shows an example of an electron microscope image of cellulose fibers loaded with coarse calcium carbonate particles, the calcium carbonate particles making up about 20% of the mass of the cellulose fibers loaded with calcium carbonate particles.
• 2 shows an example of an electron microscope image of cellulose fibers loaded with fine calcium carbonate particles, the calcium carbonate particles making up about 20% of the mass of the cellulose fibers loaded with calcium carbonate particles.
• 3 shows the ash pattern of three filter cigarettes made from a wrapping paper not according to the invention.
• 4th shows the ash pattern of three filter cigarettes made from a wrapping paper according to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

In the following, some preferred embodiments of wrapping papers according to the invention are described and compared with a wrapping paper not according to the invention.

The wrapping paper not according to the invention serving as a reference had a basis weight of 32.6 g / m ² and was made from 28% pulp fibers from coniferous woods and 42% pulp fibers from hardwoods as well as 30% free calcium carbonate particles, the percentages referring to the mass of the wrapping paper. Further properties of the wrapping paper can be seen in Table 1 in the "REF" line.

A total of 14 wrapping papers according to the invention, labeled A to K and X to Z, were produced, the composition of the wrapping papers being given in Table 1. In Table 1, "SW" in% means the proportion of pulp fibers from coniferous woods, "HW" in% the proportion of pulp fibers from hardwoods, "CF" in% the proportion of pulp fibers loaded with calcium carbonate particles and "FI" in% the proportion of free ones Fillers. The percentages are based on the weight of the wrapping paper.

The pulp fibers from coniferous and hardwood are standard products available on the market. The cellulose fibers loaded with calcium carbonate particles were obtained from Schaefer Kalk. All of the free filler was made up of precipitated calcium carbonate particles.

Furthermore, in Table 1 under “CCP” the mass of the calcium carbonate particles in the calcium carbonate particle-laden pulp fibers is given in%, based on the mass of the pulp fibers laden with calcium carbonate particles. The size of these particles is also specified as “fine” or “coarse”. In this context shows 1 an electron microscope image of cellulose fibers loaded with coarse calcium carbonate particles and 2 shows an electron micrograph of cellulose fibers loaded with fine calcium carbonate particles, as they were both used for the production of some wrapping papers according to the invention. The mass fraction of calcium carbonate particles in the cellulose fibers loaded with calcium carbonate particles 1 and 2 was about 17.3%. The pulp fibers were formed by pulp fibers from eucalyptus.

The wrapping paper X was identical to the wrapping paper REF, and the wrapping papers Y and Z were identical to the wrapping paper G. The entire surface of the wrapping paper Y was coated with a composition of 89% water, 5.5% mechanically fragmented and chemically crosslinked starch and 5.5% free calcium carbonate particles, the percentages being based on the mass of the composition. The wrapping papers X and Z were coated over their entire surface with a composition of 95.5% water, 1% mechanically fragmented and chemically crosslinked starch and 3.5% fibers loaded with calcium carbonate particles, the percentages being based on the mass of the composition. After the composition had been applied and dried, a mass of about 2 g / m ² remained on each of the wrapping papers.

The mechanically fragmented, chemically crosslinked starch can be obtained, for example, from Emsland-Starke GmbH. Table 1 paper CCP size CF SW HW FI % % % % % REF 0 28 42 30th A. 25.3 fine 42 28 0 30th B. 25.3 fine 36 24 0 40 C. 17.3 rough 21 28 21 30th D. 17.3 rough 18th 24 18th 40 E. 17.3 rough 42 28 0 30th F. 17.3 rough 36 24 0 40 G 25.5 rough 42 28 0 30th H 25.5 rough 36 24 0 40 I. 33.7 rough 21 28 21 30th J 33.7 rough 42 28 0 30th K 33.7 rough 36 24 0 40 X 0 28 42 30th Y 25.5 rough 42 28 0 30th Z 25.5 rough 42 28 0 30th

The properties of the wrapping paper REF, not according to the invention, and the wrapping papers A to K and X to Z according to the invention were determined and are given in Table 2, where “BW” is the basis weight, “EL” is the elongation at break and “AP” is the air permeability. Table 2 paper BW thickness tensile strenght Tbsp TEA white opacity AP g / m ² µm N / 15 mm % J / m ² % % cm ³ / (cm ² min kPa) REF 32.6 63 12.3 1.6 9.5 93 82 47 A. 29.6 64 7.2 1.1 3.9 92 78 81 B. 34.3 65 8.3 1.0 3.9 93 81 71 C. 29.9 63 10.8 1.4 7.5 93 78 105 D. 30.4 64 6.3 1.1 3.4 93 83 135 E. 30.5 66 9.4 1.5 6.6 93 81 102 F. 31.1 66 8.1 1.3 4.8 93 83 100 G 33.2 69 11.2 1.6 8.4 93 82 105 H 31.1 66 8.7 1.4 5.7 93 82 123 I. 30.0 65 8.9 1.4 5.7 93 80 132 J 32.8 68 11.5 1.5 8.1 93 81 90 K 30.8 64 8.5 1.3 5.4 93 82 130 X 34.6 67 16.9 1.4 10.9 92 83 42 Y 35.3 70 16.3 1.4 10.7 93 84 83 Z 35.0 71 16.8 1.3 11.0 93 85 80

From the wrapping paper REF, not according to the invention, and the wrapping papers A to K and X to Z according to the invention, smoking articles in the form of filter cigarettes with a diameter of about 7.8 mm and a length of 83 mm were produced. The tobacco used was an American blend and the wrapping papers each wrapped the tobacco. The ash appearance of these smoking articles was evaluated by an image analysis method. In doing so, three of each cigarette were lit in a vertical position and the tobacco was waited for completely to die off. A digital image of each cigarette was then taken against a neutral background under constant lighting conditions. Image analysis software then determined the proportion of non-white areas in the area of the smoldered tobacco rod. The proportion of these non-white areas in relation to the total area of the smoldered tobacco rod is expressed as a percentage and referred to as the “ash index”, whereby an average value was formed from the images of three cigarettes in each case. The higher the percentage, the more non-white areas the smoldered tobacco rod contains and the worse the consumer assesses the ash appearance.

The Ash Index measured in this way is given in Table 3. Table 3 paper Ash index % REF 11.1 A. 9.5 B. 8.6 C. 7.6 D. 4.8 E. 7.7 F. 5.8 G 6.5 H 8.2 I. 7.0 J 7.5 K 5.1 X 8.5 Y 4.3 Z 4.5

3 shows the ash pattern of three filter cigarettes made from the wrapping paper REF, which is not according to the invention. 4th shows the ash pattern of three filter cigarettes made from the wrapping paper K according to the invention. Even without quantifying the ash pattern by image analysis, the difference is already clearly visible.

The purpose of the wrapping papers A to K according to the invention was to achieve properties that were as similar as possible to the wrapping paper REF not according to the invention in order to be able to clearly show the positive effect of the cellulose fibers loaded with calcium carbonate particles. The examples are therefore not to be understood as a restriction of the invention and the person skilled in the art is able to produce wrapping papers according to the invention with, for example, different composition, different basis weight, different thickness, different air permeability or other mechanical or optical properties in the claimed range.

From Table 3 it can be seen that the Ash index of the cigarettes with wrapping papers A to K is always lower than that of the cigarettes with the wrapping paper REF not according to the invention. This means that the wrapping papers A to K result in a better ash appearance.

From Table 2 it can be seen that, as was intended in the production of the wrapping papers, the wrapping papers A to K according to the invention are very similar to the wrapping paper REF not according to the invention in terms of weight per unit area, thickness, elongation at break, whiteness and opacity. The tensile strength and thus also the energy absorption capacity of the wrapping papers A to K are somewhat smaller than in the case of the wrapping paper REF, which is not according to the invention. This is brought about by the cellulose fibers loaded with calcium carbonate particles, since the calcium carbonate particles on the cellulose fibers prevent the formation of hydrogen bonds between the cellulose fibers and thus reduce the tensile strength of the wrapping paper.

It is important that the air permeability of the wrapping papers A to K is higher than that of the wrapping paper not according to the invention. Despite this higher air permeability, the cigarettes made from the wrapping papers A to K have a better ash appearance than the cigarettes made from the wrapping paper REF. This shows that with high air permeability the use of cellulose fibers loaded with calcium carbonate particles offers a very special advantage.

If necessary, the person skilled in the art can of course reduce the air permeability of the wrapping papers A to K, for example by more intensive grinding of the cellulose fibers, and thus set the same value as for the wrapping paper REF. It is to be expected that the ash index will then decrease even further and thus the ash structure will improve even further.

A comparison between the wrapping paper I (Ash Index 7.0), which contains a total of about 36% free calcium carbonate particles bound to cellulose fibers, and the REF wrapping paper (Ash Index 11.1), which contains 40% exclusively free calcium carbonate particles, shows that the ash appearance can be improved despite the lower total content of calcium carbonate particles.

The coated wrapping papers X, Y and Z all show an improvement in the ash appearance. The papers X to Z also all have a higher tensile strength than the wrapping paper REF not according to the invention and than the uncoated wrapping papers A to K according to the invention, which is a further advantage of these embodiments.

Overall, it can be seen that the wrapping papers according to the invention can achieve a significant improvement in the ash appearance without adversely affecting the other properties of the wrapping paper and without significantly increasing the mass of the wrapping paper or adding unusual components to the wrapping paper.

Claims (35)

Wrapping paper for smoking articles, which comprises cellulose fibers loaded with calcium carbonate particles, the mass of the cellulose fibers loaded with calcium carbonate particles being at least 1% of the weight of the wrapping paper and the calcium carbonate particles in the cellulose fibers loaded with calcium carbonate particles at least 5% and at most 80% of the mass of the cellulose fibers loaded with calcium carbonate particles turn off. Wrapping paper after Claim 1 which, in addition to the cellulose fibers loaded with calcium carbonate particles, also contains cellulose fibers that are not loaded with calcium carbonate particles, and their proportion is at least 1% and at most 95%, preferably at least 10% and at most 80% and very particularly preferably at least 20% and at most 70% is based in each case on the mass of the wrapping paper. Wrapping paper after Claim 1 or 2 , in which the cellulose fibers loaded with calcium carbonate particles and, if present, also the cellulose fibers not loaded with calcium carbonate particles at least partially from a softwood, in particular from spruce, pine or fir, from a hardwood, in particular eucalyptus, birch or beech, or from hemp, flax , Jute, sisal, abaca or cotton are obtained. Wrapping paper according to one of the preceding claims, in which the cellulose fibers loaded with calcium carbonate particles and, if present, also the cellulose fibers not loaded with calcium carbonate particles are at least partially obtained from regenerated cellulose, and in particular are formed by viscose fibers, modal fibers, Lyocell® or Tencel®. Wrapping paper according to one of the preceding claims, in which the cellulose fibers loaded with calcium carbonate particles are at least partially in the mass of the wrapping paper, the proportion of cellulose fibers loaded with calcium carbonate particles preferably at least 5% and at most 80% and particularly preferably at least 30% and at most 70% is based in each case on the mass of the wrapping paper. Wrapping paper according to one of the preceding claims, which has a coating, and in which the cellulose fibers loaded with calcium carbonate particles are at least partially in the coating, their proportion in the event that the cellulose fibers loaded with calcium carbonate particles are exclusively in the coating of the wrapping paper, at least 1% and at most 30%, preferably at least 2% and at most 25%, in each case based on the mass of the wrapping paper. Wrapping paper according to one of the preceding claims, in which the calcium carbonate particles of the cellulose fibers loaded with calcium carbonate particles are formed by precipitated calcium carbonate particles, in particular by precipitated calcium carbonate particles of rhombohedral structure. Wrapping paper according to one of the preceding claims, in which the mass of the calcium carbonate particles based on the mass of the pulp fibers loaded with calcium carbonate particles is at least 10% and at most 70%, preferably at least 20% and at most 60%. Wrapping paper according to any one of the preceding claims, which further contains free fillers which are not associated with the pulp fibers, the proportion. free fillers is preferably at least 1% and at most 40%, particularly preferably at least 5% and at most 35% and very particularly preferably at least 10% and at most 30%, each based on the mass of the wrapping paper. Wrapping paper after Claim 9 , in which the free fillers are formed by carbonates, oxides, hydroxides and silicates or combinations thereof, and in particular by calcium carbonate, preferably precipitated calcium carbonate, magnesium carbonate, magnesium oxide, magnesium hydroxide, aluminum hydroxide, titanium dioxide, talc, kaolin, calcined kaolin and mixtures thereof . Wrapping paper according to one of the Claims 9 or 10 , in which the ratio between the mass of calcium carbonate particles contained in the pulp fibers loaded with calcium carbonate particles and the mass of free filler particles in the wrapping paper is 5:95 to 100: 0, preferably 10:90 to 80:20 and very particularly preferably 10 : 90 to 50:50. Wrapping paper according to one of the preceding claims, which also contains fire salts, the proportion of which is preferably at least 0.3% and at most 7%, particularly preferably at least 0.5% and at most 5% and very particularly preferably at least 0.5% and at most 3% , each based on the mass of the wrapping paper. Wrapping paper after Claim 12 , in which the fire salts are selected from the group consisting of citrates, malates, tartrates, acetates, nitrates, succinates, fumarates, gluconates, glycolates, lactates, oxyalates, salicylates, α-hydroxycaprylates, phosphates, chlorides and hydrogen carbonates, and mixtures thereof, and are particularly preferably selected from the group consisting of trisodium citrate, tripotassium citrate and mixtures thereof. Wrapping paper according to one of the preceding claims, in which at least 95% of its surface has a coating which contains free calcium carbonate particles and / or cellulose fibers loaded with calcium carbonate particles. Wrapping paper after Claim 14 , in which the coating further comprises a binding agent which is suitable for fixing the free calcium carbonate particles or the cellulose fibers loaded with calcium carbonate particles to the wrapping paper, the binding agent preferably being selected from the group consisting of starch, in particular mechanically fragmented and chemically crosslinked starch, Starch derivatives, carboxymethyl cellulose, cellulose derivatives, polyvinyl alcohol, galactomannan, gum arabic, alginates and mixtures thereof. Wrapping paper after Claim 14 or 15th , in which the coating comprises further components selected from the group consisting of fire salts, dyes, flavorings, humectants, in particular glycerol or propylene glycol, or substances for influencing the viscosity. Wrapping paper according to one of the Claims 14 until 16 , in which the coating is on the side of the wrapping paper that is on the outside of the smoking article to be manufactured from it. Wrapping paper according to one of the Claims 14 until 17th , in which the mass per unit area of the coating is at least 0.5 g / m ² and at most 10 g / m ² , particularly preferably at least 1 g / m ² and at most 5 g / m ² . Wrapping paper according to one of the Claims 14 until 18th , wherein in the coating the mass of the free calcium carbonate particles and the calcium carbonate particles of the loaded cellulose fibers in the coating taken together is at least 1% and at most 20%, particularly preferably at least 2% and at most 15% of the mass of the coated wrapping paper. Wrapping paper after Claim 19 , which additionally contains cellulose fibers loaded with calcium carbonate particles, the weight of the cellulose fibers loaded with calcium carbonate particles in the wrapping paper without the coating being preferably at least 1% and at most 60% of the weight of the wrapping paper and the calcium carbonate particles in the cellulose fibers loaded with calcium carbonate particles being at least 10 % and not more than 60% of the mass of the pulp fibers loaded with calcium carbonate particles. Wrapping paper according to one of the preceding claims, wherein the wrapping paper is intended for a cigarette and the wrapping paper has patterns or structures, preferably bands printed in the circumferential direction, in order to reduce the tendency of the smoking article to ignite measured according to ISO 12863: 2010. Wrapping paper according to one of the preceding claims, the basis weight of which is at least 15 g / m ² and at most 150 g / m ² , preferably at least 20 g / m ² and at most 120 g / m ² , and particularly preferably at least 20 g / m ² and at most 40 g / m ² , with a coating, if present, counting as part of the basis weight of the wrapping paper. Wrapping paper according to one of the preceding claims, the thickness of which is at least 10 µm and at most 200 µm, preferably at least 15 µm and at most 120 µm and very particularly preferably at least 30 µm and at most 100 µm, with a coating, if present, to the thickness of the Wrapping paper counts. Wrapping paper according to one of the preceding claims, the tensile strength of which is at least 7 N / 15 mm, preferably at least 8 N / 15 mm and particularly preferably at least 10 N / 15 mm. Wrapping paper according to one of the preceding claims, the tensile strength of which is at most 100 N / 15 mm, preferably at most 80 N / 15 mm and particularly preferably at most 70 N / 15 mm. Wrapping paper according to one of the preceding claims, the elongation at break of which is at least 0.9% and at most 3%, particularly preferably at least 1% and at most 2%. Wrapping paper according to one of the preceding claims, the energy absorption capacity of which is at least 3 J / m ² and at most 50 J / m ² , preferably at least 3.5 J / m ² and at most 35 J / m ² . Wrapping paper according to one of the preceding claims, the whiteness of which according to ISO 2470-1: 2016 is at least 80% and particularly preferably at least 90%. Wrapping paper according to one of the preceding claims, the opacity of which according to ISO 2471: 2008 is at least 70% and particularly preferably at least 80%. Wrapping paper according to one of the preceding claims, whose air permeability according to ISO 2965: 2019 is at least 0 cm ³ / (cm ² · min · kPa) and at most 300 cm ³ / (cm ² · min · kPa), preferably at least 10 cm ³ / (cm ² min kPa) and at most 250 cm ³ / (cm ² min kPa) and particularly preferably at least 20 cm ³ / (cm ² min kPa) and at most 150 cm ³ / (cm ² min kPa) amounts to. Wrapping paper according to one of the preceding claims, in which the mass of the cellulose fibers loaded with calcium carbonate particles is at least 10% of the weight of the wrapping paper and the calcium carbonate particles in the cellulose fibers loaded with calcium carbonate particles make up at least 20% and at most 80% of the mass of the cellulose fibers loaded with calcium carbonate particles and that Wrapping paper has an air permeability according to ISO 2965: 2019 of at least 50 cm ³ / (cm ² · min · kPa) and at most 300 cm ³ / (cm ² · min · kPa). Laminate comprising a wrapping paper according to one of the preceding claims and a further material whose thermal conductivity exceeds the thermal conductivity of the wrapping paper by a factor of at least two, preferably at least four, the further material preferably being formed by an aluminum foil. Smoking article comprising an aerosol forming material and wrapping paper according to any one of Claims 1 until 31 . Smoking articles according to Claim 33 wherein the aerosol forming material comprises tobacco, the smoking article preferably being a cigarette and the wrapping paper being a cigarette paper. Smoking articles according to Claim 33 , in the intended use of which the aerosol-forming material is only heated but not burned.

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